package org.bouncycastle.asn1.x509;

import java.math.BigInteger;

import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.ASN1TaggedObject;
import org.bouncycastle.asn1.DERBoolean;
import org.bouncycastle.asn1.DERInteger;
import org.bouncycastle.asn1.DERObject;
import org.bouncycastle.asn1.DERSequence;

public class BasicConstraints extends ASN1Encodable {
    // BEGIN android-changed
    DERBoolean cA = DERBoolean.FALSE;
    // END android-changed
    DERInteger pathLenConstraint = null;

    public static BasicConstraints getInstance(ASN1TaggedObject obj,
            boolean explicit) {
        return getInstance(ASN1Sequence.getInstance(obj, explicit));
    }

    public static BasicConstraints getInstance(Object obj) {
        if (obj == null || obj instanceof BasicConstraints) {
            return (BasicConstraints) obj;
        }

        if (obj instanceof ASN1Sequence) {
            return new BasicConstraints((ASN1Sequence) obj);
        }

        if (obj instanceof X509Extension) {
            return getInstance(X509Extension
                    .convertValueToObject((X509Extension) obj));
        }

        throw new IllegalArgumentException("unknown object in factory: "
                + obj.getClass().getName());
    }

    public BasicConstraints(ASN1Sequence seq) {
        if (seq.size() == 0) {
            this.cA = null;
            this.pathLenConstraint = null;
        } else {
            if (seq.getObjectAt(0) instanceof DERBoolean) {
                this.cA = DERBoolean.getInstance(seq.getObjectAt(0));
            } else {
                this.cA = null;
                this.pathLenConstraint = DERInteger.getInstance(seq
                        .getObjectAt(0));
            }
            if (seq.size() > 1) {
                if (this.cA != null) {
                    this.pathLenConstraint = DERInteger.getInstance(seq
                            .getObjectAt(1));
                } else {
                    throw new IllegalArgumentException(
                            "wrong sequence in constructor");
                }
            }
        }
    }

    /**
     * @deprecated use one of the other two unambigous constructors.
     * @param cA
     * @param pathLenConstraint
     */
    public BasicConstraints(boolean cA, int pathLenConstraint) {
        if (cA) {
            // BEGIN android-changed
            this.cA = DERBoolean.getInstance(cA);
            // END android-changed
            this.pathLenConstraint = new DERInteger(pathLenConstraint);
        } else {
            this.cA = null;
            this.pathLenConstraint = null;
        }
    }

    public BasicConstraints(boolean cA) {
        if (cA) {
            // BEGIN android-changed
            this.cA = DERBoolean.TRUE;
            // END android-changed
        } else {
            this.cA = null;
        }
        this.pathLenConstraint = null;
    }

    /**
     * create a cA=true object for the given path length constraint.
     * 
     * @param pathLenConstraint
     */
    public BasicConstraints(int pathLenConstraint) {
        // BEGIN android-changed
        this.cA = DERBoolean.TRUE;
        // END android-changed
        this.pathLenConstraint = new DERInteger(pathLenConstraint);
    }

    public boolean isCA() {
        return (cA != null) && cA.isTrue();
    }

    public BigInteger getPathLenConstraint() {
        if (pathLenConstraint != null) {
            return pathLenConstraint.getValue();
        }

        return null;
    }

    /**
     * Produce an object suitable for an ASN1OutputStream.
     * 
     * <pre>
     * BasicConstraints := SEQUENCE {
     *    cA                  BOOLEAN DEFAULT FALSE,
     *    pathLenConstraint   INTEGER (0..MAX) OPTIONAL
     * }
     * </pre>
     */
    public DERObject toASN1Object() {
        ASN1EncodableVector v = new ASN1EncodableVector();

        if (cA != null) {
            v.add(cA);
        }

        if (pathLenConstraint != null) // yes some people actually do this when
                                       // cA is false...
        {
            v.add(pathLenConstraint);
        }

        return new DERSequence(v);
    }

    public String toString() {
        if (pathLenConstraint == null) {
            if (cA == null) {
                return "BasicConstraints: isCa(false)";
            }
            return "BasicConstraints: isCa(" + this.isCA() + ")";
        }
        return "BasicConstraints: isCa(" + this.isCA()
                + "), pathLenConstraint = " + pathLenConstraint.getValue();
    }
}
